<!DOCTYPE html>
<html lang="zh-CN">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>bad domReady</title>
    <script>
      setTimeout(function(){
        document.getElementById("header").style.color = "red";
      }, 30)
    </script>
  </head>
  <body>
    <h1 id="header">这里是h1元素包含的内容</h1>
  </body>
</html>